Put °, º, and ˚ next to each other and the difference can seem trivial: three tiny raised circles. In actual text, though, each one has a different job. A small font, a scan, or a quick copy-and-paste is often enough to make them look interchangeable, especially after OCR or low-resolution reproduction.
For measurement notation, the safest question is not “which one looks right?” but “what is this mark supposed to mean?” The answer separates a degree from an ordinal abbreviation or a spacing modifier, even when the glyphs are nearly identical.
Three raised circles, three different jobs
| Character | Unicode name | Code point | Typical role |
|---|---|---|---|
| ° | DEGREE SIGN | U+00B0 | Degrees of angle; part of °C and °F |
| º | MASCULINE ORDINAL INDICATOR | U+00BA | Ordinal abbreviation in languages such as Spanish |
| ˚ | RING ABOVE | U+02DA | Spacing ring mark used in transcription and related notation |
What the degree sign ° means
° is U+00B0 DEGREE SIGN. For a plane angle it follows the number directly, as in 45° or 90°. The same character also appears inside temperature unit expressions such as °C and °F.
The degree sign does not mean Celsius or Fahrenheit by itself. In 20 °C, the C is part of the unit symbol; in 20°, the degree sign is being used as the angular unit. If you need to identify U+00B0 itself, see the degree sign guide.
Why º is not a degree sign
º is U+00BA MASCULINE ORDINAL INDICATOR. It is used in abbreviated ordinal forms in Spanish and other orthographic traditions. Its glyph is often drawn like a small raised o, which is why it can be mistaken for °.
Writing 30ºC with U+00BA is therefore not the same text as writing 30°C with U+00B0. A person may still infer the intended temperature, but a character search, parser, or validation rule can distinguish the two immediately.
What the ring above ˚ is
˚ is U+02DA RING ABOVE. Unicode places it among the Spacing Modifier Letters and describes it as a spacing counterpart of a combining ring. It is not a measurement unit symbol.
A related character is U+030A COMBINING RING ABOVE, which attaches to the preceding base character. For example, Å can be represented canonically as the letter A followed by U+030A. That combining ring is also different from the degree sign.
Normalization will not turn them into the same character
Unicode normalization is useful, but it does not turn every raised circle into U+00B0. The masculine ordinal indicator has its own compatibility behavior, and U+02DA has a compatibility decomposition involving a space plus U+030A. Neither normalizes to the degree sign.
So if a temperature or angle contains º or ˚, normalization alone is not a safe “fix.” The intended meaning has to be known before replacing the character.
Superscript zero ⁰ is another look-alike
⁰ is U+2070 SUPERSCRIPT ZERO. It is still the digit zero, only in superscript form. It should not be used as a degree sign, even if the font makes the two glyphs look close.
This is a useful reminder that visual similarity is only the first clue. Unicode text can contain several characters that occupy roughly the same visual space while carrying unrelated semantics.
Spacing can help identify the intended notation
Context often narrows the possibilities. For a plane angle, the degree sign hugs the number—45°. Celsius is different: 20 °C has a space before the complete unit symbol, while ° and C remain together.
If a temperature string contains a dedicated Celsius character instead, the related guide to ℃ vs °C explains that separate encoding issue.
A quick way to identify the mark
Start with the surrounding text, then inspect the code point when exact identity matters. A measurement of angle or a temperature unit points toward U+00B0. An ordinal abbreviation may call for U+00BA. Transcription or diacritic-like notation may use U+02DA or U+030A.
Do not decide by shape alone. Fonts can make these marks converge visually, and copied text can preserve the wrong character without making the mistake obvious on screen.
Where a wrong substitution shows up
A wrong raised-circle character can sit unnoticed because the page still looks believable. The mismatch usually surfaces later: a search misses some temperatures, a validator rejects a column, or two strings that look identical fail an exact comparison.
When that kind of accuracy matters, inspect the code point rather than trying to judge the circle by eye. The shape is a clue; the stored character is the evidence.
Choose by function, not by shape
Use ° for degrees, º when an orthographic convention calls for the masculine ordinal indicator, and ˚ only where the spacing RING ABOVE character is actually intended.
That rule is more dependable than visual comparison and still works when a font makes all three marks look almost the same.